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Copyright of Historia Agraria is the property of Historia Agraria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A paramount determinant in the selection of irrigation canal overflow configurations resides in their flow conveyance capacity. This overflow capacity is contingent upon the effective length and geometric characteristics of the weir. In the present investigation, the hydraulic performance and discharge coefficient (Cd) of circular-crested weir were scrutinized through the utilization of FLUENT software. Specifically, the study delved into the impact of geometric parameters, namely the radius and height of the crest, on these hydraulic aspects. Following the execution of calibration and validation procedures using FLUENT in conjunction with laboratory-derived data, the outcomes of the simulation revealed that augmenting the radius of the crest led to a corresponding escalation of 144.28% in the maximum pressure exerted on the crest and a 6.84% increase in flow depth. Conversely, the maximum velocity and Cd experienced reductions of 6.84% and 7.82%, respectively. The elevation of the weir height exhibited negligible influence on the maximum pressure magnitude at the crest. Contrastingly, a reduction in weir height constricted the range of pressure variations on the crest, indicating a more limited domain of pressure changes. Elevating the weir height induces a notable augmentation in the maximum flow velocity at the crest by 44.36%, concomitant with a reduction in both the depth and Cd by 52.66% and 68.96%, respectively. [ABSTRACT FROM AUTHOR]

The article discusses the architectural heritage of Mao, a city in the Dominican Republic. It states that members of the Icomos Dominicano and various heritage-related organizations visited the city's emblematic buildings and century-old irrigation canals. It mentions that Mao's foundation dates back to the Spanish colonial era, and its development has been influenced by various architectural styles, including popular and angloantillean designs.

Irrigation canal network problems are resulting from insufficient design, execution, and poor operation and maintenance. In this study, an attempt was made to evaluate the main problems of irrigation networks in Egypt and remediation measures for rehabilitation and optimal irrigation for 3.78 million ha. Recent studies, on the other hand, have shown that most of the existing networks, which have been constructed with colossal costs, suffer from various technical and social problems during the construction and operation processes. To achieve this purpose, (i) strategic planning methods and guidelines have been used to analyze and assess the irrigation networks; and (ii) field studies, visits, and organization of main and sub-main committees with stakeholder participation have been carried out, and (iii) review of literary works and holding of workshops have been applied. Based on the outcomes during the workshops and the main committee, all problems of irrigation systems were categorized into six main topics developing irrigation network systems; environmental assessment; improvement of design quality; improvement of supervision and execution; improvement of operation and maintenance; and monitoring of the system. For each topic, the existing problems in the networks were presented separately in the form of a problem diagram and then a target diagram was developed to optimize and modify the networks. An attempt was made to consider the different core criteria and set time priorities (short, medium, and long term) to determine the performance of the proposed executive and research strategies. [ABSTRACT FROM AUTHOR]

In this study, we analyze extensive segmented and standardized agricultural fields in the marginally productive terrain of the Pampa de Guereque in the Jequetepeque Valley on the north coast of Peru. Although portions of the associated canal system were constructed continuously from late Formative to Chimú times, the segmented fields date to the late Chimú–Inka period and were only partially finished, apparently never fully used, and ultimately abandoned. We provide description of field plots and irrigation canals and discuss the implications of state-level construction and labor management of the fields, as well as the probable reasons for their abandonment. [ABSTRACT FROM AUTHOR]

Copyright of History Studies (13094688) is the property of History Studies and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Located in the northwest of the Lake Van basin, the city of Malazgirt was an important area of the kingdom of Urartu from its earliest period due to its strategic location. Inscriptions of king Minua (810-785/80 bce) mention important construction projects, including fortresses, temples, and irrigation canals, in and around Malazgirt. This article deals with the Urartian presence in Malazgirt, presents new Urartian inscriptions, and considers their significance for historical geography. Particularly important is the Leter stele, which informs us of the correct reading of the name of the irrigation canal built by King Minua--Mezaiani, the antecedent form of Malazgirt. Another stele documents the agricultural activities of King Argišti (780-756 bc). [ABSTRACT FROM AUTHOR]

In rivers, irrigation canals, and drainage channels vegetation patches often appear over the bed. Flow over vegetation patches is in non-developed region which significantly influences the flow structures, thus affecting the estimation of friction factor. In the present study, the experiments were conducted in a laboratory flume to investigate the interaction of vegetation patches with turbulent flow structures evolving area over small patches. Different roughness coefficients were applied in the presence of vegetation patches, and velocity distributions, Reynolds stress distributions, and Turbulent Kinetic Energy (TKE) distributions were analyzed because they play an important role in the estimation of friction factor. Results showed that Reynolds stress and TKE at the trailing edge of vegetation patches increased due to the vertical circulation downstream of each patch. However, the vertical circulation, Reynolds stress, and TKE decreased in the flow over three patches in comparison to the flow over two patches. Results also indicated that the geometric features of a vegetation patch played an important role in the friction factor in open channels with vegetation patches on the bed. [ABSTRACT FROM AUTHOR]

As one of the fundamental natural resources of life, water and its management within ecosystems has always been the most crucial aspect of any settlement. Prior to urban modernization, water was sourced upstream from rivers or groundwater, supplying settlements, with the runoff being drained further downstream or to sea, creating a series of water flows; our livelihood coexisted with this series. In the rapid city growth led by modernization, due to the creation of uniform and homogeneous new urban areas, water flow became separated for each purpose and began to be specifically manipulated for, and by, human society. This study was designed as one of a series of research projects aiming to highlight the relationship between the historical hydraulic systems and the more recent urban spatial structure, with the focus on Valencia, one of the medium sized cities in Spain. Valencia is ideal as a case study due to the historical mechanisms of hydraulic systems still partially in use, such as irrigation canals in its agricultural regions and sewage canals in its urban areas. In more recent years, the ancient canals and the rivers that were neglected or buried, due to pollution and/or flooding concerns, began to regain significance in the face of the growing interest in and necessity of restructuring green spaces in the city as well as the preservation of the city’s unique identity and history, along with its remaining/evolving ecosystems. The purpose of our research is to interpret the interaction between Valencia’s urban morphology and its historical irrigation systems, particularly its waterways. The target period is from the modernization in the 20th century to their present conditions. [ABSTRACT FROM AUTHOR]

Aquatic weeds are unwanted plants playing an important role in different ecosystem and many of them cause enormous direct and indirect losses. In India, many irrigation canal projects are suffering from massive growth of weeds along the canal sides in addition to siltation along canal bed. It impacts hydraulic parameters like an increase in roughness impacts flowing velocity and reduction in cross-section which reduces the flow capacity of irrigation canals, thereby reducing the availability of water to farmers. The complexity of these situations has resulted in the need for assessment of the impact of weeds on the hydraulic efficiency of canals. For accurate assessment of weeds, low-altitude drone survey becomes an innovative and cost-effective solution along with ground photos. This study was carried out to identify vegetation along Right Bank Main Canal of Dudhganga Irrigation Project in Kolhapur district of Maharashtra State in India using ground photos, drone images, and high-resolution satellite data to assess the hydraulic changes to canals. The result shows an average reduction in conveyance efficiency by 23% as per measured data and transport capacity diminished by 32.79% when compared to design data due to impacted hydraulic characteristics observed during this study. [ABSTRACT FROM AUTHOR]

Copyright of Historia Agraria is the property of Historia Agraria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Santa Cruz River, like all the major rivers in southeastern Arizona and the region, had a permanent year-round flow that was restricted to limited segments of the river. This is where the Sobaipuri O'odham established their villages because the reliable surface flow allowed them to farm with irrigation canals. Early historical period observations indicate that the Santa Cruz and other regional rivers were characterized by patchworks of pasturelands, agricultural fields and canals, shady groves of mature trees, marshes, and expanses of dry sand, in contrast to the many previously suggested reconstructions. The underlying fundamentals of the river valley have been determined by surface water availability and although periodically transformed by floods, downcutting, drought, and human factors the riparian corridor has regenerated. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the necessity of quantifying and correcting seasonal 3D effects on 2D electrical resistivity tomography (ERT) data measured along the embankments of rivers or artificial canals. A permanent ERT monitoring system has been continuously operating along the levee of an irrigation canal in Mantua province, Italy, since September 2015. To evaluate the importance of 3D effects and their dependence on seasonal variations, we first performed numerical simulations and also laboratory tests on downscaled levees of the study site. The results showed that 2D apparent resistivity pseudosections measured along the levee are significantly affected by 3D effects of the embankment geometry. Moreover, it was observed that 3D effects not only depend on the levee geometry, but they are also affected by seasonal fluctuations in the water level in the canal. This proved the importance of calculating 3D effects for the study site during dry and irrigation periods. Therefore, different synthetic models based on the levee geometry and water level in the canal in each period were constructed in RES2DMOD and RES3DMODx64 to quantify 3D effects for the study site. The ratios of apparent resistivity values calculated in RES3DMODx64 to the values calculated in RES2DMOD showed that 3D effects approach a maximum of 30% when the canal is empty during winter, and they arrive at a maximum of 10% when the canal is filled with water in summer. Using the graphs of the modelled 3D effects as a function of electrode spacing, apparent resistivity pseudosections measured by the permanent ERT system are corrected for 3D effects to obtain reliable resistivity sections after inversion. The final resistivity maps can be then converted into water content images using the empirical and site‐dependent relationship developed from core samples in the study area. Water content maps can be used to evaluate the stability of the levee and to detect possible seepage zones. [ABSTRACT FROM AUTHOR]

With the increases of world fish consumption and stagnation of wild fish catches, the contribution of aquaculture to world fish production has steadily increased from 25.7% in 2000 to 46.8% in 2016. Integration of aquaculture in irrigation canals, respectively dual use of the same water, first for fish production and later for irrigation is a relatively new technological concept, used to maximize the efficiency of water use, by designing and locating removable installations and establishing technologies for rearing fish in small bodies of water ( irrigation canals). The CM LUNCA irrigation canal on which the experiment took place was artificially built in 1969 and serves a very large agricultural area; is part of the irrigation network of Covurlui Plain and is managed by A.N.I.F., Southern Moldova branch. The irrigation system of which C.M.L. is part of, consists of the main pumping station SPA Dunărea, 6 pumping stations SPR, 21 pressure stations SPP, 37 canal motor pumps, 126 km irrigation canals. The Lunca Magistral Canal has a length of 19240 m and stretches from km 78.4 of the Danube from where it makes its outlet, passes behind Lake Brateș and reaches close to Vânători commune. The Danube pumping station is the main station of the Covurlui Plain (S.P.A.) subsystem and takes the water from the Danube river through the gravitational outlet with a flow of 54 mc/s. The distribution of water on the canals is ensured by the main dam, which has three openings with cofferdam and flat dams. The water from the C.M.L. currently irrigates only 5566 ha, located on the first terrace (surface that requires about 3m/s), and the surplus is intended for the upper terraces, which require a pumping height Hp = 90m. The adaptation of the carp species to rearing in floating fish cages from the CM Lunca canal was made in a time interval between 3 and 7 days from the population of the ponds, at a density of 150 ex/m3 and a distance from the crown of the dam between 17,5m and 30,5m. [ABSTRACT FROM AUTHOR]

In this paper, a review of the state of the art of the control strategies used for the water distribution control in irrigation systems is developed, aimed at increasing the operability of these systems, as well as reducing water losses due to operation. The historical advances of this kind of control systems are shown. Finally, some of the challenges of the international scientific community are offered to continue improving the capability and performance of the controllers used in irrigation systems. [ABSTRACT FROM AUTHOR]

The main motto behind the performance assessment of an irrigation system is to utilize the available water resources in an efficient and effective manner. In recent times there has been a growing concern that performance in the context of irrigated agriculture is less than that had been anticipated. Deficit water supply results in loss of production, while excess water delivery leads to waterlogging and salinity. Water supply at any given location is often poorly matched to crop need and is highly variable in both time and discharge. Good performance is not only a matter of high output, but also one of efficient use of available resources. In the present study, evaluating the performance of a canal system was conducted in two parts of Hirakud canal system namely Paramanpur distributary and Senhapali distributary. The flow measurement was done using flow tracker ADV, an instrument which measures the flow with relatively more accuracy. Various indicators of performance in a flow irrigation system, such as adequacy, variability, efficiency, inequity, conveyance performance, and irrigation performance were used to evaluate the performance of the canals. The evaluation indicates that more attention should be given for the canal operation strategy to get optimal output from the system. [ABSTRACT FROM AUTHOR]

Les gravures rupestres protohistoriques de la région du mont Bego, situées dans les Alpes-Maritimes, sur la commune de Tende, comprennent plus de 40 000 gravures figuratives, telles que des corniformes, des poignards, des hallebardes, des haches, des réticulés, des réticulés à appendices, des plages rectangulaires ou ovales, des anthropomorphes, des figures géométriques et des cercles rayonnant que nous considérons comme des idéogrammes et plus de 60 000 signes non figuratifs, tels que des cupules isolées, des groupes de cupules isolées, de petites plages de cupules, des nuages de cupules éparses, des barres, qui bien que non figuratives sont toutes hautement significatives. Toutes ces gravures, inscrites sur plus de 4150 roches réparties sur 1500 hectares, dans huit hautes vallées montagnardes, réalisées le plus souvent au moyen de petites cupules, n'ont pas été effectuées au hasard. Elles ont été tracées en relation avec les préoccupations économiques, les mythes cosmogoniques et les traditions culturelles des peuples agriculteurs et pasteurs de l'Âge du Cuivre et de l'Âge du Bronze ancien des Alpes méridionales au cours de rites propitiatoires. C'était une période correspondant à l'optimum climatique du Chalcolithique où, pendant l'été, dans les basses vallées, les champs cultivés et les pâturages s'asséchaient. Les préoccupations économiques des populations qui occupaient alors les régions situées de part et d'autre des Alpes méridionales étaient essentiellement tournées vers la recherche de l'eau pour irriguer champs cultivés et pâturages, ainsi qu'en témoignent les pétroglyphes inscrits sur les roches : des lignes sinueuses évoquant des ruisseaux ou des canaux d'irrigation, des plages rectangulaires ou ovales, figurant des bassins de rétention d'eau, des cupules isolées, des groupes de cupules isolées, des plages de cupules ou des nuages de cupules éparses figurant la pluie, ou encore des réticulés, qui représentent les champs cultivés et les pâturages, reliés à des trous ou à des fissures naturelles évoquant les sources et les ruisseaux. Au cours de rites propitiatoires, les graveurs s'adressaient au dieu de l'orage, maître de la foudre et dispensateur de la pluie fertilisante, à la grande déesse, déesse-Mère ou déesse-terre, les bras levés en position de réceptivité pour recueillir la pluie du ciel et pour apporter au printemps, avec le retour de la végétation, l'abondance aux humains. The protohistoric rock engravings of the region of Mount Bego, located in the Alpes-Maritimes, in the municipality of Tende, include more than 40,000 figurative engravings, such as corniforms, daggers, halberds, axes, reticulates, appendage reticulate, rectangular or oval beaches, anthropomorphs, geometric figures and radiant circles that we consider as an ideogram and more than 60,000 non-figurative signs, such as isolated cupules, isolated cupules of cells, small beaches of cupules, scattered clouds of cupules, bars, which although not figurative are all highly significant. All these engravings, inscribed on more than 4150 rocks spread over 1500 hectares, in eight high mountain valleys, most often made with small cups, were not carried out at random. They have been traced in relation to economic concerns, cosmogonic myths and cultural traditions of the farming and pastoral peoples of the Copper Age and the Early Bronze Age of the Southern Alps during propitiatory rites. It was a period corresponding to the climatic optimum of Chalcolithic where during the summer, in the lower valleys, cultivated fields and pastures dried up. The economic preoccupations of the populations who then occupied the regions located on both sides of the Southern Alps were essentially turned towards the search for water to irrigate cultivated fields and pastures, as evidenced by the petroglyphs inscribed on the rocks: sinuous lines evoking creeks or irrigation canals, rectangular or oval beaches, water catch basins, isolated wells, isolated wells, wells or scattered cups of rain or reticulates, which represent cultivated fields and pastures connected to natural holes or cracks that evoke springs and streams. During propitiatory rites, the engravers addressed the god of the storm, master of the lightning and dispenser of the fertilizing rain, to the great goddess, goddess-mother or goddess-Earth, arms raised in a position of receptivity for collect rain from the sky and bring in spring, with the return of vegetation, abundance to humans. [ABSTRACT FROM AUTHOR]

Stuckenia pectinata is an invasive submerged weed in the irrigation district in the lower valley of the Colorado River, Argentina. The objective of this study was to analyze the initial growth of S. pectinata from tubers, and its annual growth cycle in irrigation canals, in order to be efficient in adapting future control techniques. Tubers were planted in aquaria in order to evaluate the effect of their size, depth of burial and below zero temperatures on the initial growth. Under field conditions, samples of plants were collected from two irrigation canals, from October to March, in two complete growth cycles. Plant height and biomass of the leaves, stems and spikes were measured. The largest tubers were able to emerge from deep burial and generated larger plants than the smallest tubers. Frozen tubers did not germinate at any burial depths. Maximum biomass in the irrigation canal reached 1660 g DM m-2 with a peak at the beginning of summer. The elimination of biomass at the end of the irrigation season would result in small tubers that would die in the winter time. The information generated could lead to more appropriate and sustainable control. [ABSTRACT FROM AUTHOR]

Irrigation canals network in Egypt for all levels suffer from water deficit and un-equitable distribution of irrigation water among beneficiaries. So, its modernization became omnipresent to overcome the problem of water shortage by the end of canals. One of the improvement sectors of irrigation canals network is replacing an earthen mesqa by upraised lines or buried pipes. The hydraulic performance of the improved irrigation system is explored using a case study canal, where buried pipes system is applied as improved mesqa system. The case study is for the Hadaya canal which is one of the distributary canals that located in Assiut governorate. This canal services 19 mesqas with different lengths and area served. The hydraulic performance of mesqas is examined through different scenarios of operation of the mesqa pumping station and area served. Three scenarios of mesqa valves operation are considered .The first scenario is when all valves are operated at the same time all over the week. The second is when one valve operates for two days per week and the third is when all valves operate for one day. Also, three scenarios are considered for pump operation 14, 16 and 18 hours per day. Moreover, effect of different scenarios of mesqa operation on sudden transition of flow in pipes due to pump shut-down is studied. EPANET software was used for the hydraulic analysis. It was found that operating the pump 14 hours per day fulfill the minimum monthly cost. Also, operating the outlet valves according to scenario no. (3) gives the least operating cost. The maximum velocity in the pipeline is less than 1.2 m/s for all operating scenarios. Besides, effects of mesqas off-takes on the flow in distributary canal are studied. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Innumerable falls are to be provided in irrigation canals where ground slope exceeds the permissible bed slope of a canal. In the conventional method of design, fluming ratio is fixed arbitrarily irrespective of inflow Froude's number. Long lengths of inlet and outlet transitions are provided to prevent flow separation. Transition and dissipation structures are kept separate resulting in high costs. Hydraulic performance of the conventional fall structure is also not so satisfactory. Analytical and experimental studies were conducted by the author to find an efficient and economic method of design of falls. Optimum fluming ratio and optimum length of transitions are found both for economy as well as efficiency. An efficient and economic stilling basin with rapidly diverging side walls and adversely sloping floor, which act simultaneously as energy dissipater and transition, has been recommended. An example has been worked out to illustrate the design procedure of the proposed canal fall. [ABSTRACT FROM AUTHOR]

In this research, a reliability-based method for optimum design of the capacity and operation policy for a water resource system including a reservoir and the downstream irrigation network is presented in which important stochastic hydrological, agronomic and economic factors are considered. The developed model is applied for the Marboreh reservoir and the irrigation network in west of Iran in the form of a stochastic mathematical program with the objective function of maximizing the net benefit gained from the crops' production limited to the hydrologic constraints associated with the reservoir and soil moisture of the plants' root zone and the agronomic constraints related to the crops. The decision variables are design parameters of the reservoir capacity, irrigation network area and the crops pattern and the operation parameters which include reservoir operation policy, water allocation to the crops and the irrigation strategy. The uncertain factors considered are the inflow to the reservoir, the water demands, the crops yield, the price of crops and the production costs. Genetic algorithm is used as the optimization routine and a Monte-Carlo routine takes into account the effect of the stochastic outcomes of the uncertain factors. Results state the optimal capacity of 161.8 MCM for the reservoir, area of 31,304 ha for the irrigation network and a volumetric reliability of 72.1% in the neutral to risk condition. In the risky state, the network area is increased and the reservoir capacity and the reliability index are decreased while in the risk-averse state the results are vice versa. [ABSTRACT FROM AUTHOR]

Abstract The natural hydrologic processes that create and maintain the diversity of aquatic and riparian habitats along the World's streams and rivers have been profoundly altered by humans. Diversion of surface water to support production agriculture in arid and semi-arid regions has degraded ecosystems but also created potential habitat along and in canals specifically designed to transport water. The prevalence of canals and the immense amount of water used for agriculture have created these new artificial stream systems. This study demonstrates the potential for irrigation canals to support riparian and aquatic communities similar to natural streams in urban/residential and agricultural landscapes. We examined the hydrological and ecological characteristics of streams and irrigation canals in urban and agricultural landscapes in northeastern Colorado, typical of regions dominated by irrigation-supported agriculture. Flow patterns in canals depended on their size and had a range of patterns with potential ecological consequences such as rapidly rising and falling water stage, intermittent dry periods, and delayed peak and base flows compared to natural streams. Despite these hydrologic differences, the taxonomic and functional composition of riparian plant and aquatic macroinvertebrate communities indicated that ecological similarities exist between streams and canals, but are dependent, in part, on their landscape setting with stronger similarities in agricultural areas. We also tested the influence of characterizing taxa by functional groups using physiology, ecology and life history traits to explore attributes of habitats including woody canopy structure and water quality. We used a Habitat Quality Index (HQI) that combined physical and biological measures into a single index. Streams scored higher on average within agriculture and urban/residential settings compared to canals; however, one third of urban canals scored above the average of agricultural streams. This multidisciplinary study shows that irrigation canals can be valuable riparian and aquatic habitat, especially in regions with severely degraded streams. Graphical abstract Unlabelled Image Highlights • Irrigation canals are more prevalent in some semi-arid agricultural landscapes. • Riparian vegetation of irrigation canals showed similarities to local streams. • Aquatic macroinvertebrates of irrigation canals were similar to local streams. • Land-use affected similarities between canals and streams. [ABSTRACT FROM AUTHOR]

Abstract Seepage from irrigation canals can be controlled by interceptor pipe drains located down slope of the canal embankment and parallel to the canal. HYDRUS (2D/3D) is a software that simulates water flow in two-dimensional variably-saturated porous media. This software is used to determine the average water contents of the upper layers, direction of flow and the seepage rate to the pipe drain for different values of evaporation rates, pipe diameters, and horizontal and vertical pipe offsets from the conveyance canal. The results showed that increasing the vertical offset (drain depth) increases the drain discharge. Moreover, increasing the horizontal offset reduces the canal seepage and lower the phreatic surface. The proposed approach can determine drain size and location to cut off canal seepage, ensuring no contribution to the water body under the irrigated lands beyond the drain. The approach accounts for realistic soil formations and considers both saturated and capillary flows. [ABSTRACT FROM AUTHOR]

Highlights • Numerical model validated by laboratory column and flume experiments on nanoparticles. • Nanoparticles enhance density-driven flow effects. • Trapping of nanoparticles within periodic bedforms is expected. Abstract A carbon solution composed of nanoparticles (d 50 = 85.7 nm) was used in experiments designed to explore nanoparticle transport characteristics within the hyporheic zone of a riverbed. Experiments and numerical simulations demonstrated that nanoparticle transport in the hyporheic zone is affected by hydraulic head gradients due to river flow-bedform interactions as well as density gradients associated with the nano-carbon solution. Differences with similar flow/transport situations were examined, and it was found that particulate-enhanced density can change hyporheic transport appreciably. In addition to density, particle settling enhances downward movement of the nano-carbon plume in the riverbed. While nanoparticle transport in the upper hyporheic zone is largely controlled by advection due to flow driven by head gradients at the bed surface, density gradients and particle settling influence the transport process significantly in the lower hyporheic zone. During the transport process, nanoparticles become deposited due to attachment to sand particles and filtration by small pores in the bed. Compared with transport where density variations are minimal, the particulate-induced density gradient induces downward transport of nanoparticles and entrained liquids, leading to deposition/accumulation at the base of the bed. Graphical abstract Image, graphical abstract [ABSTRACT FROM AUTHOR]

Examines the litigation in the 1880s and 1990s over water rates between the California-based privately-owned canal and irrigation company San Joaquin & Kings River Canal & Irrigation Co. and the farmers dependent on it. Question on who owned the water right; Questions on fair return to a public utility; Profile on the company; Ruling by Judge William Morrow in 1911.

Improving the efficiency of main Agricultural Water Conveyance and Delivery Systems (AWCDS) has a significant impact on improving water productivity in agriculture. Therefore, risk assessment of mentioned systems is necessary to increase reliability of operational performance. Accordingly, this study for the first time presents a unique framework to assess the adequacy, equity, and efficiency of agricultural water distribution and delivery risk assessment within AWCDS. In this way, the Fault Tree Analysis (FTA) technique is employed for risk assessment of “undesirability of supply and delivery”. The west Dez main irrigation canal in Khuzestan province of Iran was determined as the case study of the research. A set of questionnaires filled up by managers and experts of this irrigation district, the failure probabilities of the basic events are gathered in the form of linguistic terms. Due to the uncertainty in these terms, the system’s risk assessment to determine the failure probability of the top event was performed based on Fuzzy Fault Tree Analysis method (FFTA). The results of the study showed that the failure probability in the fuzzy approach is 0.55 which is roughly 0.15 more than crisp approach. Also, the rating of the basic events based on their contribution to the occurrence of the top event was carried out using importance measures. Five major events were identified with an emphasis on operational and socio-economic issues related to distribution and delivery of water. Comparing the results of risk assessment with the mathematical model reveals that the latter’s failure probability will be less than the system’s FTA due to non-consideration of some important factors. [ABSTRACT FROM AUTHOR]

The study area consists of a Reference site and two Polluted sites which are distinguished by virtue of the nature of combined effluent received by wheat (Triticum aestivum) grown in the agricultural fields. All the growth and yield parameters viz; Average spike weight per plant, Average number of grains per spike, Average weight of grains per spike, Average shoot length, Average biomass per plant with spike and Average weight per grain of wheat at Polluted site II exhibited increase in comparison to the Reference site while Average spike weight per plant, Average number of grains per spike and Average weight of grains per spike at Polluted site I exhibited a decrease in comparison to the Reference site. This is attributed to the fact that at Polluted site II there is direct mixing of combined effluent into the irrigation canal leading to dilution of combined effluent which is used for irrigating the agricultural fields whereas at Polluted site I there is lateral seepage of combined effluents from the drain carrying effluents into the agricultural fields. Hence, combined effluent in diluted form is showing stimulatory effect on wheat and vice-versa. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Journal of Experimental Biology (Botany) is the property of Egyptian Society of Experimental Biology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In a traditional automated upstream controlled canal with a downstream buffer reservoir, the process to fill the buffer reservoir requires one step: the inflow to the canal is increased, and the flow change eventually arrives at the buffer reservoir. This paper describes an attempt to shorten the time necessary to stabilize the new flow rate at the buffer reservoir. The method requires calculated, remote manual adjustments to all the canal check structure gate positions in addition to two flow rate changes made at the head of the canal, followed by a return to automated upstream control. The method was tested in the Upper Main Canal of the Central California Irrigation District both through simulation and in the field. With a canal flow of approximately 20% of the maximum, simulation modeling predicted that a flow rate change arrival at the reservoir would be about 5.5 h in a typical operation, with final stabilization in about 16 h. Simulation of an improved procedure indicated an almost instantaneous increase in flow at the reservoir of half the flow change, with final flow stabilization at 11 h. The field test resulted in almost the full flow change arriving at the reservoir after about 20 min, with gradual stabilization occurring over the next 11 h. Important differences between simulation and actual results are discussed. [ABSTRACT FROM AUTHOR]

The drag-based Savonius hydrokinetic turbine (SHT) has an enormous potential for small-scale power generation from free-flowing water and it can be deployed especially at sites remote from existing electricity grids. These turbines can be installed in waves, tides, ocean currents, natural flow of water in rivers, manmade channels and irrigation canals to produce power. The performance of a SHT are highly influenced by its design parameters such as blade profile, number of blades, overlap ratio and aspect ratio. Although, over a period of nine dacade since its invention, serveral studies have been carried out, however, no particular concencus on the optimum design of SHT is arrived. In view of this, in the present investigation, as attempt has been made to parametrically evaluate the performance of the SHT through experimental and computational fluid dynamics (CFD) analysis. The SHT under investigation has been developed in-house. Initially, a comparison of performance between two- and three-bladed SHT with conventional semicircular blades has been carried out experimentally where their maximum power coefficients are found to be 0.28 and 0.17, respectively at their corresponding tip-speed ratios of 0.84 and 0.67. Further experiments with a two-bladed SHT turbine with elliptical blades have shown its inferior performance as compared to the two-bladed semicircular SHT. The reason behind the enhanced performance of the two-bladed semicircular SHT is then analyzed through two-dimensional CFD simulations. Finally, the experiments are conducted at various immersion levels, where the performances of the SHTs are found to degrade with a decrease in immersion. However, the two-bladed semicircular SHT maintains to have a better performance than the others. [ABSTRACT FROM AUTHOR]

The stiff competition for water between agriculture and non-agricultural production sectors makes it necessary to have effective management of irrigation networks in farms. However, the process of selecting flow control structures in irrigation networks is highly complex and involves different levels of decision makers. In this paper, we apply multi-attribute decision making (MADM) methodology to develop a decision analysis (DA) framework for evaluating, ranking and selecting check and intake structures for irrigation canals. The DA framework consists of identifying relevant attributes for canal structures, developing a robust scoring system for alternatives, identifying a procedure for data quality control, and identifying a MADM model for the decision analysis. An application is illustrated through an analysis for automation purposes of the Qazvin irrigation network, one of the oldest and most complex irrigation networks in Iran. A survey questionnaire designed based on the decision framework was distributed to experts, managers, and operators of the Qazvin network and to experts from the Ministry of Power in Iran. Five check structures and four intake structures were evaluated. A decision matrix was generated from the average scores collected from the survey, and was subsequently solved using TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) method. To identify the most critical structure attributes for the selection process, optimal attribute weights were calculated using Entropy method. For check structures, results show that the duckbill weir is the preferred structure while the pivot weir is the least preferred. Use of the duckbill weir can potentially address the problem with existing Amil gates where manual intervention is required to regulate water levels during periods of flow extremes. For intake structures, the Neyrpic® gate and constant head orifice are the most and least preferred alternatives, respectively. Some advantages of the Neyrpic® gate are ease of operation and capacity to measure discharge flows. Overall, the application to the Qazvin irrigation network demonstrates the utility of the proposed DA framework in selecting appropriate structures for regulating water flows in irrigation canals. This framework systematically aids the decision process by capturing decisions made at various levels (individual farmers to high-level management). It can be applied to other cases where a new irrigation network is being designed, or where changes in irrigation structures need to be identified to improve flow control in existing networks. [ABSTRACT FROM AUTHOR]

While geoarchaeology as a practice within archaeology grew out of many historical roots, a major role has been the explication of site formation processes and site-level contextual analysis. In recent years, geoarchaeological research has branched out to encompass larger geographic scales, and to play a greater role in environmental archaeological investigations. This paper argues that geoarchaeology has a great deal to contribute to the understanding of human history and to archaeological theory through the application of multiscalar approaches that place human behavior in a physical, environmental and ecological context and by creating linkages between physical processes and human responses. We use geoarchaeological data from the Yellow River valley to show that drainage/irrigation canal and bank/levee building had commenced in the lower reaches by ca. 2900-2700 cal B.P. The emphasis on flood plain flood control infrastructure was a result of long-term increases in sedimentation caused by large populations farming with increasingly efficient technologies in the fragile environments of the Loess Plateau. Ever increasing sedimentation set in motion a cycle of further investment in flood control works eventually leading to a massive flood catastrophe in the first 20 years of the first millennium A.D. as the Yellow River exceeded natural and human geomorphic thresholds that constrained it in its previous course. These floods arguably triggered the social and political events that brought down the Western Han Dynasty but the root causes are clearly more complex. Geoarchaeology thus contributes to an understanding of the multiple causes and consequences of large-scale social and political collapse. [ABSTRACT FROM AUTHOR]

In northwestern Italy, traditional rice cultivation using permanent flooding has been replaced by cultivation that uses a reduced water depth and a shortened submersion period. Prey availability for the numerous herons and egrets using this intensive rice cultivation region changed as well, with a diminution of amphibians and an increase of crayfish (Procambarus clarkii) and oriental weatherfish (Misgumus anguillicaudatus). The prey intake in 2014 was compared with data available for 1987 for the three most common species of waterbirds that forage in the paddies. Total biomass intake by Grey Herons (Ardea cinerea) feeding in the paddies decreased from 28 g dry mass/min in 1987 to 7 g in 2014, and by Black-crowned Night-Herons (Nycticorax nycticorax) from 8 g to 5 g, while the intake by Little Egrets (Egretta garzetta) remained similar (12 and 13 g in 1987 and 2014, respectively). The observed levels of prey intake allowed breeding Grey Herons to meet their energy needs by feeding exclusively in the rice paddies in 1987, but not in 2014. The other two study species could not meet their daily requirements for successful breeding by feeding in the paddies only, either in 1987 or 2014. Yet the three species bred successfully in the study area, and their reproductive output remained stable both in 1987 and 2014. Successful breeding was probable by the three species foraging in other habitats, such as rivers, small natural wetlands and irrigation canals, in the region. [ABSTRACT FROM AUTHOR]

The paper is dedicated to the development of methods of waterproofing curtains arrangement for seepage protection of irrigation canals. The analysis of the informational sources in the field of seepage protection of irrigation canals has been conducted together with the use of horizontal directional drilling and the bentonite usage. The innovative technology of such works is proposed. The gist of the innovative technology is the combination of horizontal directional drilling and waterproofing bentonitecontaining mortar injection. The laboratory experiments of the protective curtain arrangement are conducted. Bentonite powder concentration per unit of volume of hardening mortar, discharge pressure (supply) of injection mortar, and duration of mortar supply are chosen as the most influencing technological factors. Soil filtration coefficient is selected as the most important indicator. It is concluded that the combination of values of low bentonite powder concentration and relatively high discharge pressure allows obtaining lowest soil filtration coefficient values. [ABSTRACT FROM AUTHOR]

The roughness coefficient of the concrete irrigation canal is one of the important evaluation criteria to ensure the hydraulic performance or malfunction between water and wall surface. In this study, the roughness coefficient of the concrete irrigation canal was measured using the aerial ultrasonic wave of the transceiver type sensor. The effect of the dispersion of measurement values in relation to the arithmetical mean roughness and the peak to peak value of the reflected wave were demonstrated. The influence of wet and dry conditions of concrete surface and the verification of the measurement range were taken into account. Results obtained showed that the peak to peak value of the reflected wave could measure the arithmetical mean roughness of concrete. It was observed that the average of 15 measured values was sufficient for accuracy. The peak to peak value of the reflected wave was affected slightly under wet condition. The range of the measured diameter of aerial ultrasonic wave sensor was approximately 300 mm and 600 mm from the distance of 550 mm and 1000 mm respectively. It is concluded that the development of the measurement method of arithmetical mean roughness of concrete surface by the transceiver type aerial ultrasonic sensor can be achieved. [ABSTRACT FROM AUTHOR]

We measure the impact of road and irrigation projects on the livelihoods of households in the poorest and most remote areas of Vietnam using difference-in-difference estimators. We find that both rural road and irrigation projects help local households improve the access to safe water and welfare measured by a wealth index. The impact of irrigation projects is found to be larger than the impact of road projects. We also find heterogeneous impacts of road and irrigation projects. Households with higher levels of education tend to benefit more from road projects, while households with lower levels of education are likely to benefit more from irrigation projects. [ABSTRACT FROM AUTHOR]

Article impact statement: In many investigations, the collection of long‐term data are often overlooked, but necessary for understanding key hydrological processes that guide the development of conceptual models and evaluation of predictions. [ABSTRACT FROM AUTHOR]

Supplying agricultural water has recently become more challenging due to increase in drought frequency in semi-arid regions. Unreliable supply water resources lead to inflow fluctuations in irrigation districts locating at the downstream part of the rivers. The conventional operation cannot handle the fluctuations effectively; therefore, water delivery to the off-takes is seriously compromised. In this study, the capability of decentralized Proportional-Integral (PI) and centralized Linear Quadratic Regulators (LQR) controllers were investigated to alleviate the effects of severe inflow fluctuations in the main irrigation canals operation. In this regard, the Roodasht North Branch (RNB) main canal, located in the central Iran, consisting of 24 reaches was selected as a test case. Mathematical operational model of the canal was coupled with the designed PI and LQR controllers. The performance of the controllers were evaluated under the normal and severe unpredictable inflow fluctuations scenarios. The results showed that the PI configuration was able to successfully deal with and handle the normal inflow fluctuations. Water delivery to the upstream and middle canal reaches was regulated reasonably well, while the downstream canal reaches were still slightly suffering from the inflow fluctuation. The LQR controller showed an outstanding performance in dealing with both normal and severe inflow fluctuation test scenarios. The controller optimally adjusted the gates accordingly to manage even the sever inflow fluctuation. The results of this study demonstrate capabilities of the control configurations in managing the inflow fluctuations in main canals which can help moving towards the urgent needs for improving the current canal operational performance. [ABSTRACT FROM AUTHOR]

The paper presents the design, implementation and field tuning of the (SCADA) system of a Portuguese irrigation canal network upstream controlled by AMIL radial gates and equipped with other Neyrpic devices. In addition to the irrigation district and its main hydraulic system, the paper also presents SCADA architecture, including two synoptics, and their remote terminal units (monitoring and controlling as well as monitoring units). The SCADA manual controllers - direct, gate position and gate flow controllers - are defined for the intakes of main canals and main distributors, in order to permit a pre-defined flow value or a daily flow schedule achievement. SCADA also monitors outflows from the main canals and main distributors - the most important canal-top-side weirs and terminal weirs of the canal. The developed manual gate flow controllers were tuned in the field using collected data readings from two types of acoustic Doppler flow meters. The field procedures for tuning the flow controllers and the obtained parameter values are also presented. [ABSTRACT FROM AUTHOR]

Southwest of Tarapacá Valley, in the Pampa Tamarugal of northern Chile, the remains of a canal were discovered running south for more than 6 km. Mapping and excavations indicated that this narrow (about 3 m) and shallow (about 0.5 m) construction was intended to divert water from the perennial Tarapacá River, combine this with occasional run-off from the mountains to the east, and irrigate a system of agricultural fields in a depression on the pampa. Several piles of rocks (cairns) and cleared lines (geoglyphs) were seen in the vicinity of the canal. The recovered pottery sherds were identified as belonging to the Pica-Charcollo tradition (800–1500c.e.), while four radiocarbon dates from excavated wood and charcoal clustered around 1400–1600c.e. This places the canal around the time of the colonization of the area by the Inka Empire, which made Tarapacá Valley into a regional center for mining and marine resources. The rationale behind its construction is likely a combination of the need to mitigate fluctuations in the availability of water for agriculture and the production of a larger food surplus. [ABSTRACT FROM PUBLISHER]

The work presented here is an extension of previous papers that updated the calibration of round (Armco-type) meter gates (three sizes: 0.30, 0.46, and 0.61 m), developed ratings for rectangular gates (two sizes: 0.46 and 0.61 m) on round pipes, and examined errors and uncertainty related to using these devices for water discharge measurement. Previous works examined gate discharge ratings under low supply-channel flow velocity perpendicular to the gate discharge pipeline. Here, additional testing was conducted to test the hypothesis that higher velocities in the supply channel would show decreased meter gate flow compared to the low-velocity ratings, but that the published gate calibration method would still yield accurate flow-rate calculations. All testing was conducted in a test facility with the gate discharge pipe set perpendicular to the supply channel, as is common in field installations. Velocities up to 0.94 m=s (3.1 ft=s) were tested with the smaller gate and 0.66 m=s (2.2 ft=s) for all other gates. These velocities are on the upper end of velocities found in common earthen irrigation canals (and in many lined channels at the farm delivery level) in California. Interestingly, results indicate that the Froude number of the supply-channel flow did not have a statistically significant (at an α-level of 0.01) influence on gate discharge coefficients. Discharge percent error and uncertainty were examined to compare the discharge coefficients presented in the literature to the discharge measured during the testing at different supply-channel velocities. Under recommended operating conditions, the uncertainty was within ±5% without adjustments for supply-channel velocity. This extended work supports earlier recommendations that meter gates can be an accurate flow measurement device for farm water delivery flow measurement if installed and operated correctly. [ABSTRACT FROM AUTHOR]